View Full Version : Condensation??
Hey Guys,
I just bought an Oware bivy sack--my first bivy. I took it out for a test run last night with a Western Mountaineering down bag (went down to about 45 last night in Alabama), and when I woke up this morning there was some pretty serious condensation on the bag, enough so that the moisture sort of brought out the scent of the down, if you know what I mean. Is this a problem? It just unpacked it a few minutes ago back at the house and it seems fine, but I plan on using this setup to thruhike next summer. Will this kind of condensation hurt the bag if it happens routinely?
Thanks for any tips.
Footslogger
12-20-2006, 10:54
Hey Guys,
I just bought an Oware bivy sack--my first bivy. I took it out for a test run last night with a Western Mountaineering down bag (went down to about 45 last night in Alabama), and when I woke up this morning there was some pretty serious condensation on the bag, enough so that the moisture sort of brought out the scent of the down, if you know what I mean. Is this a problem? It just unpacked it a few minutes ago back at the house and it seems fine, but I plan on using this setup to thruhike next summer. Will this kind of condensation hurt the bag if it happens routinely?
Thanks for any tips.
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It would take quite a bit of condensation to totally foul a down bag ...but it could happen. If the bag were to begin soaking through the down would clump and it would be like sleeping in a wet sock. Good news is that if given half a chance a down bag will dry out from minor condensation and won'd suffer permanent damage.
All bags begin to loose their comfort rating starting with the first use. Repeatedly getting a down bag wet may well accellerate that process.
I carried a down bag on my thru in 2003 and used a single walled silnylon tent that suffered from condensation now and then. What I did was to spray a DWR (durable water repellant) coating on the outer surface of the bag. That caused moisture to pulddle and run off the bag rather than soak in.
Consider giving that a try. Other than that ...the one thing I haved done now and then to keep my down bag(s) lofting is to place them in a large commercial dryer with some tennis balls and spin it for 20 minutes or so. That breaks up any clumps or consolidation that has developed and seems to keep the bag's warmth.
'Slogger
Hey Guys,
I just bought an Oware bivy sack--my first bivy. I took it out for a test run last night with a Western Mountaineering down bag (went down to about 45 last night in Alabama), and when I woke up this morning there was some pretty serious condensation on the bag, enough so that the moisture sort of brought out the scent of the down, if you know what I mean. Is this a problem? It just unpacked it a few minutes ago back at the house and it seems fine, but I plan on using this setup to thruhike next summer. Will this kind of condensation hurt the bag if it happens routinely?
Thanks for any tips.
From what I've read (but not from personal experience) condensation is the major problem with bivvies. And of course down is particularly prone to losing its loft when wet.
Two Speed
12-20-2006, 11:11
...the one thing I haved done now and then to keep my down bag(s) lofting is to place them in a large commercial dryer with some tennis balls and spin it for 20 minutes or so. That breaks up any clumps or consolidation that has developed and seems to keep the bag's warmth.
'SloggerSmee and Peter Pan, of Jack's R Better fame, recommend putting their down quilts, underblankets, etc, in a dryer with a couple of tennis balls after every hike for 10 or 15 minutes. IIRC they recommend no heat. Evidently rolling the critter around in the dryer with the tennis balls along with the air flow keeps everything hunky-dory. Been doing that with my Moonstone Lucid for about a year and things are going pretty well.
'Slogger, do use any heat or just the fluff setting?
Toolshed
12-20-2006, 11:11
You didn't mention if you kept the bivy closed or were breathing into the bivy but that is one large source of condensation. the other is the quart or so of moisture you lose every night as you sleep, via perspiration. This will flow through the down bag and condense on the outer shell of the down bag or on the inside of the cold bivy and then soak back into the shell of the down bag.
Though as moisture continues to collect, the performance of down will start to diminish I wouldn't worry too much about it - just make sure you keep airing your bag out as much as possible - during breakfast, lunch stops and breaks. Also when you get to camp, unless it is really damp out, open you bag up and let it air.
I find that on sunny days, hanging a down bag over a makeshift clothesline or tree branch in full sunlight does wonders to dry it out - especially darker bags. Nothing like crawling back into a completely dry down bag on the 5th or 6th day of your trip.
Also, unless you leave it out in the rain and it gets soaking wet, the moisture that comes from perspiration usually spreads/migrates through various sections of the bag pretty evenly, so you won't have a really wet clump in any one spot, with exception to feet. I find feet give off an awful lot of moisture at night and the foot box might become damper. But even so, the moisture will migrate through the down so that it all becomes slightly damp, but not much, much more damp in any one spot. (I hope this makes sense)
As others have mentioned, the major problems with bivy sacks is the ventilation issue.
The East is more humid than the drier (and higher elevevation) West. Bivy sacks were originally designed for high altiture mountaineering. They work pretty well in the colder and higher elevations.
Having said all that, you may want to not seal up your bivy all the way. The temp you mentioned (45F) is rather warm for a bivy. I suspect that Alabamba is a also bit more humid than say Colorado (or even NH) in the winter. I am not overy familiar with your bivy, so not sure what venting options it may have.
As for down, I am a big fan of low-heat and tennis balls in town. "In the field", take advantage of any sun to air out the bag a bit.
FWIW, have used the same down bag for all my hikes from 1997 on. Never had a problem with it being soaked through (even when I lived on the East coast).
It's probably not what you want to hear, but if you pitch a tarp over the bivy it should draw the condensation. Or, if you're able set up under a leafy branch and not in the open. It doesn't have to right under, something you can stand under should be fine.
Well I personly had some bad experiants with down and I use a synthitic bag with primaloft and I do fine with my hubba tent, which is so much lighter than a wet bivy and down bag the next morning. sorry had to say it. na the bag, tent and my bag are under 6 pounds. So if you plan on taking all that on a thru hike its realy up to you. Hike your own hike, but im doing a thru hike this spring. Im taking my REI nooksack, hubba tent and golite pack. But hope to see you out there.......Fons
Footslogger
12-20-2006, 11:43
'Slogger, do use any heat or just the fluff setting?
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When I actually WASH the bag I use the low heat setting in the dryer.
If I'm just "tuning up" the bag I use cold/fluff setting.
'Slogger
Oh yeah ...and the more tennis balls the better, in my experience. Over time in the tumbler some of them tend to end up trapped inside the foot end of the bag (even if it's unzipped). By adding more tennis balls (I use 12) there is pretty much always enough bounce action to separate and fluff the down.
Two Speed
12-20-2006, 11:48
"In the field", take advantage of any sun to air out the bag a bit.Yeah, I try to do that at every "boots off" break. FWIW the Moonstone Lucid has a flat black liner, which I consider an advantage because it seems to pick up more heat than a lighter color. Most of the bags I've seen recently seem to have dark liners so that may be a positive trend.
. . . By adding more tennis balls (I use 12) there is pretty much always enough bounce action to separate and fluff the down.Dang, I'm surprised there's any room left for the sleeping bag!
Footslogger
12-20-2006, 11:50
Dang, I'm surprised there's any room left for the sleeping bag!
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Well ...I'm talking about a big commercial dryer and the sleeping bag and tennis balls are the only things going round and round.
'Slogger
Toolshed
12-20-2006, 14:29
...FWIW, have used the same down bag for all my hikes from 1997 on. Never had a problem with it being soaked through (even when I lived on the East coast).
Ditto on Mags. I still use my 1983 EMS Robson Long -25d bag in the winter and it works great. I also have 5 (or is it 6?:confused: ??) other down bags that I have had since 89-94 and no problems with loss of loft. Only as the nlyon ages, I lose a few tufts of down nightly on every trip now.
Down is awesome. I still have and use the first down bag I ever bought, back in 1970. It has about 2.5 lbs of fill... and cost $60 from some hunters' outfitter shop in Rochester NY. The Slumberjack down bag that I bought in Damascus VA in 1990 is still used on all my summer section hikes.
Yep..down is more dollars in the short term, but you can not beat a down bag for the long haul.
vipahman
12-20-2006, 17:16
Hey Guys,
I just bought an Oware bivy sack--my first bivy. I took it out for a test run last night with a Western Mountaineering down bag (went down to about 45 last night in Alabama), and when I woke up this morning there was some pretty serious condensation on the bag, enough so that the moisture sort of brought out the scent of the down, if you know what I mean. Is this a problem? It just unpacked it a few minutes ago back at the house and it seems fine, but I plan on using this setup to thruhike next summer. Will this kind of condensation hurt the bag if it happens routinely?
Thanks for any tips.
Weather permitting, try ventilating the bivy sack a couple of minutes during the night. Your bag will still be warm but the condensation will be much less if non-existant. Don't breathe into the bivy. Wear protection (balaclava, googles, hat, etc) for exposed portions of your face/head.
I use a OR Deluxe bivy and still get condensation on my WM bag. Bivies are just so tight against the sleeping bag material that there's not a lot you can do about it. Other than try with more breathable bivies such as Epic material. They weren't made for humid environments. Single-wall tents have the same problem, it's just a bigger bivy with more ventilation options.